In general, a TV signal in NTSC standard or PAL standard is composed of a luminance signal and a chrominance signal, and the TV signal is generated by combining the luminance signal and the chrominance signal on a carrier signal. After receiving the TV signal, the luminance signal and the chrominance signal will be separated and recovered from the carrier signal so as to display video signal on a TV screen. However, if the separation of the luminance signal and the chrominance signal from the carrier signal is not processed completely, some of the luminance signal may penetrate into the chrominance signal, or some of the chrominance signal may penetrate into the luminance signal, which results in a false video color signal displayed on the TV screen. In addition, a back-end control processor performing controlling process based on the image information displayed on the TV screen will be likely to cause an error detecting result due to the false video color signal displayed on the TV screen, and which in turn will cause inaccurate process.
The output of a front-end circuit is usually transmitted based on image field style. Since a frame is composed of two image fields having different polarities, a frame can be recovered for displaying on the TV screen by the back-end circuit through a de-interlacing process. It is well known that the suppression of false video color signals is normally processed based on a frame or a plurality of image fields having different polarities, which consumes larger bandwidth provided by the system and requires extra buffer memories.
For that reason, the present invention provides a method and related apparatus for restraining erroneous image colors to solve the aforementioned problems.